Technical Field
The present invention relates to controlling transmission of content data among a plurality of transmission terminals.
Description of the Related Art
An example of a transmission system that transmits or receives content data between a plurality of transmission terminals via a relay device includes a videoconference system that carries out videoconference via a communication network such as the Internet. There is an increasing need for such videoconference systems due to reduction in business trip costs and time in recent years. In such a videoconference system, a plurality of videoconference terminals, which are examples of transmission terminals, is used. A videoconference can be carried out by transmission or reception of image data and sound data between these videoconference terminals.
In addition, the recent improvement of broadband circumstances contributes to transmission/reception of high-quality image data and high-quality sound data. Accordingly, it becomes easier to detect the circumstances of a communication partner in a videoconference, and hence conversation-based communication becomes more productive.
The same communication terminal (or of the same type) may be used for different applications or purposes. For example, in the case of using a transmission terminal for remote diagnosis system, an image of the affected part of a patient needs to be sent to a remote place. It is thus preferable that image data be of high quality. In contrast, in the case of using a communication terminal for a videoconference system for merely conveying a message, image data may be of low quality.
However, there is a general tendency that the higher the quality of image data and sound data, the more expensive the usage fee of a transmission system. Therefore, in the case of using the same transmission terminal (or of the same type) for different applications or purposes, if the user is unable to select a communication quality that suits a particular application or purpose, the user may eventually pay a wasteful usage fee.